| (19) |
 |
|
(11) |
EP 2 460 912 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
22.08.2012 Bulletin 2012/34 |
| (43) |
Date of publication A2: |
|
06.06.2012 Bulletin 2012/23 |
| (22) |
Date of filing: 29.11.2011 |
|
| (51) |
International Patent Classification (IPC):
|
|
| (84) |
Designated Contracting States: |
|
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL
NO PL PT RO RS SE SI SK SM TR |
|
Designated Extension States: |
|
BA ME |
| (30) |
Priority: |
01.12.2010 JP 2010268841
|
| (71) |
Applicant: Japan Super Quartz Corporation |
|
Akita-shi
Akita 010-0065 (JP) |
|
| (72) |
Inventors: |
|
- Sudo, Toshiaki
Akita-shi
Akita 010-0065 (JP)
- Kitahara, Ken
Akita-shi
Akita 010-0065 (JP)
- Suzuki, Koichi
Akita-shi
Akita 010-0065 (JP)
- Yamazaki, Shinsuke
Akita-shi
Akita 010-0065 (JP)
|
| (74) |
Representative: Gulde Hengelhaupt Ziebig & Schneider |
|
Patentanwälte - Rechtsanwälte
Wallstraße 58/59
10179 Berlin
10179 Berlin (DE) |
|
| |
|
| (54) |
Vitreous silica crucible |
(57) Provided is a vitreous silica crucible which is resistant to deformation and corrosion
even when heated at high temperature for a long time. There is provided a vitreous
silica crucible of the present invention including a substantially cylindrical straight
body portion, a curved bottom portion, and a corner portion smoothly connecting the
straight body portion and the bottom portion, wherein a wall of the vitreous silica
crucible includes, from an inner surface side, a transparent layer and a bubble-containing
layer, and a ratio of a thickness of the bubble-containing layer with respect to a
thickness of the transparent layer at an intermediate position between an upper end
and a lower end of the straight body portion is 0.7 to 1.4.